Inflated article and method of making the same



May 7, 1935. c, s. MCCHESNEY 2,000,452

INFLTED ARTICLE AND METHOD OF MAKING THE SAME Original Filed Dec. 29,1951 INVENTOR Caf/L Ee M @Hes/WSH ATTORNEYS Patented May 7, 1935 l y IlINFLA'IED ARTICLE AND METHOD oF MAKING 'rHEsAME Cuyler S.McChesney,Kenmore,N. Y.; assignor' to Dunlop Tire andRubber'Corporation, Buffalo, N.Y.', a corporation of New York v Originalapplication December 29, 193.1', SerialNo. i Y 583,640; Divided and thisapplication'February 16, 193,4, Serial No. 711,453

Claims. (CLIS- 55) 'I'he present invention is a division ofco-pendholding yparts or retainers thereof suitable Vfor ing applicationSerial No. 583,640 filed December carrying out the methodof myinvention. 4 29, 1931. y Fig. 2 is asection ofthe molds and retainers Myinvention 'relates to the manufacture of taken" on a plane atrightangles to that of Fig. f 5 inflated articles such as tennis orr otherballs, the l, the mold parts being shown 'partly 'in section 5 interiorspace of which is filled with a gas under and partly in side elevation.y j Y -v a` pressure. It relates to constructions enabling. Figs'. 3 and4 arev dtail' SeCtQIlal VBWSv 0f a D01- a more perfect sealing of thewalls of the article tion of a kmold and of a ball positioned therein tobe obtained and provides means for effectively Shown respectivelyinclosed and slightly opened forming and filling the article with gasunder positions. y I iv pressure in an inexpensive, simple marmer, Fig.5 is a detail sectional view on'a somewhat .Inflated balls and similararticles have heretcenlarged scale of two halves' or partsof an articlefore been lled with gas under pressureby insertabout 'Gd be jOiIlBCl.ing a hollow needieinto the .bau through which YIn my invention a pair0f Vnfmldng elements 15, the g'as under pressure is supplied and thenseal- 01'v mOld halves containing recesses to 'form one 154 ing the wallof the ball, or in placing within the 0r more articles are mounted incorresponding ball a material that decomposes to a gas during retainersor retainer shells` in 'an apparatus the curing or vulcanization, Eachof these methwhereby these retainers and the mold halves or ods hascertain disadvantages. VThe balls may elements may be brought intovcomplementary 2O aISO be Aiilled with gas under pressure when closedrelationship so that the retainer parts or 20 formed of two halves byjoining these ha1vesin shells form a lC'Ompleteii chamber- One 0f the anatmosphere of gas under pressure, and then mOld 'Darts S movable Within'its respective Tecurin'g. This latter method, however, is dimtainer orshell toleave a slight space between cult and troublesome to carry outand is usually its face and the opposed face. of the other mold wastefulofv gas. part and is sealed againstthesides of the re- 25 Objects of -myinvention .parete avoid the 0btainer or Vrshell so thatthi's-spacebetween the jections and `'disadvantages in the previous methmold halvesis 'Sealed against COmmunCatOn With ods of forming and inflating hollowarticles, and the Sheller-retainer outside of the mold part. to providea method in which the balls or other The gas with which the articles areto be in- 30. articles may be formed of halves or parts while flated issupplied t0. thS'enClOSed Sealed Spa@ 30 the inner spaces Vof vsaidparts are filled with any between the mold halves under pressure atwhich desired gas under pressure, and in which the the articles are tobe inflated `so that the space parts or ,halves are then joinedsubstantially within the` mold cavities, and which contains the withoutthe use of gas other than that supplied parts to be joined to formthearticle, is iilled with 35. toV said interior spaces; and further,-to vprovide the desired gas at the desired pressure. There-f v35apparatus in which' the parts to be joined may upon the' movable moldhalf is forced toward the be easilyV andreadily placed in position forjoinopposite mold until their adjacent facesmeet and ing and may be heldproperly positioned in the seal the mold cavities, containing the` moldapparatus during the joining of the parts. halves, to form the completedarticle,'this sealing,

40 y. A further object of the vinventionfis to protherefore, takingplace whilethe article halves 40 vide article parts or halves suitablyshaped readare inflatedwith thegasat the desired pressure. ily to form aseal of the greatest tightness against As the mold parts are forcedtogether, al1 excess escape of gas andv to be'easily placed and held gasis expelled back through the supply pipe. in proper position inapparatus ofthe above type, Thev mold halves'are then heated by steam,or

and'to form a finished ball or hollow article havother suitable means,until the parts are cured, 45 ing a more perfect seal where the variousparts, whereupon the molds are cooled and opened, the of whichvthe ballor article is formed, are joined. gas supply pipe meanwhile having beenclosed.

With these and other objects in view which The mold retainers or shellsmay` then be opened will more fully appear from the following deand thecompleted articles taken from the molds.

scription, the invention resides in the article and `The mold retainersor shells are so mounted 50 methodsfdescribed and pointed out in thefoland formedv that when opened they yare swung lowing specications andclaims. to position to enable `the article halves to be The variousfeatures are illustrated in the readily placed in proper position in themold secaccompanying drawing, in whichj tionsand tobe positively andaccurately heldin gFig. 1 is a vertical sectional View of molds andposition for joining when the molds are closed.

beveled edge of its complementanypartand.forms` a more positive, rmerseal therewith. 2

Referring more particularly V`to .-.the apparatus,

illustrated in Figs. 1 and 2`-of .the accompanying drawing, in shell I0or retainer is mountediel mold half or part 26. The edge of this mold,which may be of circular or other shape, fits the inner `surface yof`the :side :wall 21 of the -mold retainer vor `yshell `I-II :and has anexposed :surface spanning the area within the 4side walls 21 :andprovided with a number of semi-spherical recessesv 28 .ofdimensionscorresponding .to the vsize of -th balls to be formed. 1 i

The mold part :26 is slidably mounted inthe retainer ID so thatitmayfslideidownwardly therein .until .its jlower wall ,-28 contactswith, and is stopped by, the bottom wall 30 of the retainer IIL thismovement., however, being :'a relatively slight one. It -may move-outwardly-,of the retainer I0 until its front or exposed face contactswith'a face of a complementary mold 3l in rthe upper retainer `I2.mounted-in `fixed positioniin theretainer I2. The outward movement of:the mold 26 `mayialso'be Irestrained by a shoulder .32 von the inneredge vor surface of the wall 21 lwhich fit-s Iinto a. fcovrrespendingniche 33 in the mold ipart V26.`

The space between 'the `rear walls 29 and 36 o'f the mold part 26 andretainerrln, respectively, is sealed from `thefront face .of the mnld insuch 'a manner that Kluids supplied under pressure to either ofthe abovefaces cannot Aescape ito Vthe other. This fis preferably accomplished bya circumferential rpacking 34 set into a recess Vin the sidewall `211 of-the retainer shell 10. "This packing may be pneumatically pressedtoward the wall of the mold half 26 by fluid pressure supplied through aduct 35 to the channel surrounding the packing '34.` A similar packing'36 is provided in the edge of the wall 21 that lcontacts `with the-corresponding circumferential wall 31 `of the upper shell or retainerI2 so that when these two parts are brought together, a `tight seal maybe made between them. I

When the apparatus is in open or charging position, each recess 28 inthe lower mold partr 26 is lled with a hollow heini-spherical half 'orsection of rubber as indicated at '3 8 .in Figs. 3 and 4. Correspondingor complementary hemispherical recesses 39 in the Aupperniold part 3Iare accessible to the operatorkwhen the parts are opened and separated,and are similarly supplied "ith hollowhemi-spherical sections or halves40,. When all of the mold has thus been supplied with heini-sphericalparts, the parts I0 'and' I2 are placed in closed position as showninFigs. 1 and 2. During or prior to closing, themold half 26 will beresting on the lower wall 30 of the lower mold retainer or shell I0 sothat the opposing faces of the mold halves 26-and` 3| donot abut but areslightly spaced, as indicated in Fig. 4 of the drawing. The edgesbetweenlthe hemi- `in4 :application Serial No. 583,640.

The ,-mold 3 I fmay'be, andprefera'bly is,

spherical halves 38 and 40 to be joined to the completed article arealso slightly spaced, as shown in Fig. 4, giving access between theinterior of these parts and the space between the opposing faces of themold halves 26 :and 3I.

The mold retainers or shells I Il and I2 are thereupon tightly locked inposition as described When the mold shells have been locked in closedposition,

fluid under Vpressure is admitted through the `duct 35 to the packings34 and 36, causing the latter .to tightly seal the edge walls of thelower mold part '26 vand the abutting edges of the mold 'shells-orretainers I0 and I2, respectively.

, A supply of gas with which the articles are lto be filled, and underthe pressure at which .they ,are to be filled, is then admitted througha supply pipe 52 to a duct 53 in the upper mold part l3I `which leads tothe space between these two mold parts. This space, as indicated at -54in Fig. LLand `also thelspace within the two hemispherical halves 38 and40, are thus filled with gas at the desired pressure. Thereupon thelower .mold part. .25 is forced against this pressure,

upwardly into close contact with the upper mold.

part `3| 'bringing the two opposed 'faces of the molds Vtightly togetherand eliminating the space 54.

The gas contained in this space isthereby forced back through the duct53 into the supplyA pipe 52 sothatthere remains in the apparatus onlythevgas within the heini-.spherical halves 3'8y and '40. The mold half 26may be forced upwardly by any suitablemeans as, forexample, by fluidunder greaterpressure than that supplied through the pipe 52, andadmitted through the inlet pipe 54, Fig. 2, between the wall 29 o'f thelower mold part 26 and the wall 30 of the retainer shell.

The articles are now completely assembled and inflated. Steam is thenadmitted to steamchambers 55. in the mold through pipes 56 and 51 and isalso admitted to steam chambers 58 in the movable mold 26 through pipeconnections 59 and 60 which are threaded into the mold 26 and passedthrough Asuitable packings 2I and 62, respectively, in the wall 30 sothat these pipe connections may move with the movement .of the mold 26.

When the articles have been suiiiciently cured, cooling water may beadmittedV to the steam chambers 55 and 58 through the respective pipeconnections 56, 51, 59 and 60. Thereafter the pressure in the supplypipe54 is released. The pipe 52 is vdisconnected from-the source of gasandconnected with air under pressure which thereupon forces the` mold 26away from the mold 3| and back to its 'original position. Then thepressure on the lines I I and I2 is released.

To ensure that the two halves 38 and 40 to be molded shall be in theirproper position in the mold recesses, the former rare provided withbeads 68 and 69, respectively, slightly spaced from and parallel'to theplane of the edges of these halves, and these beads fit into suitablypositioned recesses 10 and 1I, respectively, in the surfaces of the moldrecesses. When the operator inserts the two halves to be molded into themold recesses, therefore, the beads 68 and 69 fitting into the recesses10 and 1I, accurately position the halves and also serve to hold them inthis position while the molds are being moved into closed position.

It will be understood that any suitable and satisfactory type of jointmay be used between the two halves 38 and I0.

In the case of a spherical object or ball, the type of joint shown inFigs. 3, 4 and 5 is very desirable. In this joint the edge of one part40 is beveled inwardly on an angle to the plane of the edge indicated atB. The edge of the other part is beveled in a complementary direction,but on a larger scale than complementary angle as, at A. Inasmuch as theangle A is greater than the angle B, the beveled face 12 of this halfwill not reach and intersect the inner spherical surface of the part ifit be made of the same width as the beveled edge 13 of the part 40. Theedge between the beveled face 12 and the inner surface of the part 3Bwill, therefore, be blunted, as at 14, although this is not strictlynecessary, and the edge 12 may extend further toward the inner surfaceof the sphere than indicated in Fig. 5.

In any event, however, as the two parts are brought together, the edge14 will strike the tapered surface 13 before the two parts arecompletely assembled and the tapering edge 12 will, therefore, be forcedinwardly against a certain outward resistance. This causes the two edges12 and 13 to be forced together with a positive sliding friction whichpresses them into the most intimate contact and with the least amount ofcement to hold them together. The pressure within the two parts alsoacts to press the edges 12 and 13 together, as a certain component ofthis pressure acts normal to these two surfaces. The above joint is,therefore, especially suited for use in the apparatus.

1. A hollow resilient wall article formed of two halves joined on aseam, the edge of said seam being inclined to the plane of juncture ofsaid halves so that the edge of one half overlaps the edge of the other,the angle of the overlapped part of the seam being more acute than thatof the overlapping edge and being depressed inwardly by the latter.

comprises supporting complementary article parts in spaced positions ina conned space, causing gas to flow from a supply of gas under pressureto ll said space with gas under pressure of said supply, bringing saidarticle parts together to enclose and seal gas under pressure in thehollow article thus formed, and reducing the space about said article tosubstantially cornplete elimination to force the gas in said spaceoutside said article back into said supply.

4. A method of molding hollow articles which comprises supportingcomplementary article parts in spaced positions in a confined space,iilling said space with gas under a predetermined pressure, bringingsaid parts together and sealing them in complementary positions to forma complete whole that encloses gas under pressure while contracting'said space to substantially the volume of said completed article.

5. A hollow resilient wall article formed of two halves joined on aseam, the edge of said seam being inclined to the plane of juncture ofsaid halves so that the edge of one half overlaps the edge of the other,the angle of the overlapped- Y part of the seam being more acute thanthat of the overlapping edge and being depressed inwardly by the latter,each half having a continuous external bead spaced slightly from theseam.

CUYLER S. MCCHESNEY.

